Improvement in metallic piston-packings



UNITED STATES PATENT Orrrcn.

VAN I-I. HIGGINS, or cHIeAeo, ILLINOIS.

IMPROVEMENT IN METALLIC PISTON-PACKINGS.

Specification forming part of Letters Patent No. 146,591, dated January 20, 1874 application fledj Aprn s. 1873. f

To all whom it may concern:

Be it known that I, VAN H. HIGGINS, of the city of Chicago, in` the county of Cook and State of Illinois, have invented certain new and useful Improvements in Metallic` Piston- Packing for SteamEngines, of which the foloffthat portionof the ring which receives theI tongue, and Fig. 6 a plan view of the tongue.

As metallic packing-rings have heretofore been constructed, the whole of the exterior surface of the ring comes in contact with the interior of the cylinder, and the whole of the interior surface receives the pressure of the steam, so that the ring is pressed against the cylinder with great force, and an unnecessary amount of force is expended `in overcoming the friction between the exterior of the ring and the cylinder. My invention consists in so constructing the solid portion of the pistonfhead and the ring that only a portion of the interior of the ring is subjected to the pressure of the steam.; in cutting away a portion of the `exterior surface of the ring, so that the steam acts upon the recessed part, partly counterbalancing the pressure upon the interior of the ring, and diminishing the friction between the ring andcyh'nder; and in the devices and combinations herein claimed. y

In the drawings, A represents the pistonrod, BB, the solid or so-called spider portions of the piston-head, the interior of which may be made as usual. A part, b, of B is smaller than the main portion, forming a shoulder at g. C C are the metallic packingrings surrounding the parts B B. rlhey have on the inside a shoulder, tting theV shoulder g, forming a steam-tight joint, and preventing the passage of the steam to the inside of that i part of the ring marked a, which surrounds the main part of B. Between the remaining part c of the ring and the smaller portion b of Bthere is aspace, n, into which steam enters.

A portion, I', of theV exterior of the rings is cut i There is an away, to which steam passes. opening between the two ends of the rings, as usual, (see Fig. 5,) and a part of each` end of that part of the ring marked c is cut away,

as shown in Fig. 5, to receive the tongue d,

the form of which is shown in Figsl 2, 3, 6, its inner surface having a recess, fi, tting the parts s s, Fig. 5, to one of which it is secured. A portion of the outer surfaceof thistongue d comes upvflush with the exterior surface of the main portion of the ring, preventingthe i.

passage of steam into the opening between the ends of the ring, `butthe remainder of the tongue is cut away somewhat, so as to allow steam to pass between it and the cylinder. D

D are end covers or followers-one over eaclr` end. 0n the inside of eachis a recess, e, `A which communicates with the space n between i the interior of the ring and the part b of B. Steam enters the recess e through the holes h.

The portion r of the exterior of the ring which is cut away is less in width than the widthof the interior portion of the ring the steam behind it, and the amb p ure upon the interior of the ring depends upon the difference in width of these two parts.

The several parts are heldin position by the nut E. i

In operation, steam passes through the ope A ings h into the recess e on the insideof the cover D, thence into the space n between the portion c of the ring and the part b of B. At`

ends of the ring, and, the shoulder upon the inside of the ring forminga steam-tight joint with the shoulder g on B, steam cannot pass between the part a of the ring and the main part of B, but the tongue d beingrsecured to one end of the ring only, the `ring his free to expand. I prefer to leave a little spacebetween the free end of the tongue d and that portion of the end of the ring opposite thereto, into which space steam can pass as soon as it enters the cylinder, aiding in expanding theY ring.

Wllat I claim as new is as follows:

1. The solid portion B of a piston-head,\vl1en provided with a shoulder, g, in combination With a packing-ring having a corresponding shoulder on its inside, forming, with the shoulder g, a steam-tight joint, substantially as and l for the purposes specified.

2. The packing-ring C, recessed upon the exterior, and constructed upon its interior so as to allow the steam to have access to onlT a portion of its interior, and used in connection with the parts 4B and D of suitable construcionl, substantially as and for the purpose set ort 1.

3. The packing-rings C, When recessed upon the outside and provided with tongues d, in combination with the parts B B and covers D, all constructed and operating substantially as and for the purposes specified.

VAN H. HIGGINS.

Witnesses E. A. WnsT, O. W. BOND. 

